1. Field of the Invention
The present invention relates to an air outlet device for a vehicle cabin (hereinafter referred to as “vehicle-cabin air outlet device”), such as a center register, a side register, a lower register, or a side defroster.
2. Description of the Related Art
Conventionally, there exists a vehicle-cabin air outlet device of a type which includes a rectangular tubular body which forms an air guide passage; a plurality of front-side parallel wind-direction adjustment plates rotatably supported inside the tubular body at a front end thereof; a plurality of rear-side parallel wind-direction adjustment plates which are perpendicular to the front-side wind-direction adjustment plates and rotatably supported inside the tubular body at a position shifted rearward from the front end by a predetermined distance; and an operation knob which is assembled to a selected one of the front-side wind-direction adjustment plates to be slidable along a longitudinal direction thereof. The operation knob is operatively connected to a selected one of the rear-side wind-direction adjustment plates via a connection mechanism. When the operation knob is slid on the selected front-side wind-direction adjustment plate along the longitudinal direction, the rear-side wind-direction adjustment plates are swung in a mutually interlocked manner.
The tubular body, the front-side wind-direction adjustment plates, and the rear-side wind-direction adjustment plates of a vehicle-cabin air outlet device of such a type are resin molded products formed from a synthetic resin material. In general, these constituent members are separately molded, and the vehicle-cabin air outlet device is assembled through an assembling operation of mounting the front-side and rear-side wind-direction adjustment plates to the tubular body one after another. Therefore, because of a larger number of parts, the assembly of the vehicle-cabin air outlet device requires a large number of assembly steps, which makes the assembly work troublesome.
Recently, in order to cope with the above-described drawback, there has been proposed a molding method. In this method, the rear-side wind-direction adjustment plates or the front-side wind-direction adjustment plates are molded as a group. Also, in this method, a connection rod for connecting the rear-side wind-direction adjustment plates or the front-side wind-direction adjustment plates each other and/or a support plate for rotatably supporting the rear-side wind-direction adjustment plates or the front-side wind-direction adjustment plates is molded with the group within the same molding die, and the molded rear-side wind-direction adjustment plates or front-side wind-direction adjustment plates are assembled to the connection rod and/or the support plate (see Japanese Patent Publication (kokoku) No. H4-69542). This molding method has already being put into practical use, and there has been proposed a vehicle-cabin air outlet device which is referred to as a “register” and which is configured by making use of the above-mentioned molding method (see Japanese Patent No. 3329670). In the method of manufacturing the register proposed in the latter Japanese Patent, a plurality of vertical blades, which correspond to the rear-side wind-direction adjustment plates, and a retainer, which corresponds to the tubular body, are molded in the same molding die, and the vertical blades are assembled into the retainer within the molding die.
Incidentally, in an air outlet device of such a type, an operation knob, which is assembled to a selected one of front-side wind-direction adjustment plates to be slidable along a longitudinal direction thereof, is operatively connected to a selected one of rear-side wind-direction adjustment plates via a connection mechanism; and when the operation knob is slid on the selected front-side wind-direction adjustment plate along the longitudinal direction, the rear-side wind-direction adjustment plates are swung in a mutually interlocked manner. The complex structure of the connection mechanism may possibly hinder performance of the above-described molding method, and the structure of the connection mechanism may possibly influence the operability of the operation knob. The latter Japanese Patent proposes a connection mechanism which can cope with these problems.
In the register proposed in the Japanese Patent, the connection mechanism is composed of a first connection mechanism portion provided on a selected one of the rear-side wind-direction adjustment plates, and a second connection mechanism portion provided on the operation knob side. FIGS. 6 and 7 show the connection mechanism of the register, and FIG. 8A schematically shows a state where all the vertical blades are molded within the same molding die.
The register, which is denoted by reference numeral 10, includes a retainer 10a, which is a rectangular tubular body for forming an air guide passage; a horizontal blade group 10b composed of a plurality of horizontal blades which are arranged in parallel in the vertical direction and rotatably supported inside the retainer 10a at a position near a front end opening thereof; a vertical blade group 10c composed of a plurality of vertical blades which are arranged in parallel in the horizontal direction and are rotatably supported inside the retainer 10a at a position shifted rearward from the horizontal blade group 10b by a predetermined distance; and a connection mechanism 10d for operationally connecting an operation knob to the vertical blades. These constituent members are formed of a synthetic resin material.
The vertical blade group 10c, a connection rod 13e (which will be described later) for connecting the vertical blades of the vertical blade group 10c together, and a support plate 13f (which will be described later) for rotatably supporting the vertical blades are molded in a molding die 10e schematically shown in FIG. 8A. The molding die 10e is configured to enable the vertical blades of the molded vertical blade group 10c to be assembled to the connection rod 13e and the support plate 13f within the molding die 10e. Notably, in FIG. 8A, reference numeral 10e1 denotes a stationary die half, reference numeral 10e2 denotes a movable die half, and reference character PL denotes a parting line at which the movable die half 10e2 can be separated from the stationary die half 10e1.
In the register 10, as shown in FIGS. 6 and 7, an operation knob 12 is assembled to a selected horizontal blade 11 located at a central portion in the horizontal blade group 10b. The operation knob 12 is assembled to the horizontal blade 11 to be slidable in the horizontal direction (the longitudinal direction). The connection mechanism 10d is formed between the operation knob 12 and a selected vertical blade 13 located at a central portion in the vertical blade group 10c. The connection mechanism 10d is composed of a first connection mechanism portion 10d1 provided on the vertical blade 13 and a second connection mechanism portion 10d2 provided on the operation knob 12 side.
The first connection mechanism portion 10d1 includes upper and lower flat support plate portions 13a and 13b integrally formed at a front-side intermediate portion of the vertical blade 13, and left and right connection pillar portions 13c and 13d having an elliptical cross section and integrally formed at front portions of these support plate portions 13a and 13b such that the connection pillar portions 13c and 13d are biased leftward and rightward, respectively. A front-side wall portion of the vertical blade 13 between the support plate portions 13a and 13b is formed to have a rearward concaved arcuate cutout. Such a structure of the first connection mechanism portion 10d1 enables the movable die half 10e2 to be separated from the stationary die half 10e1 at the parting line PL, serving as a reference line. The vertical blade group 10c provided with the first connection mechanism portion 10d1 is assembled to the connection rod 13e and the support plate 13f so as to form an assembly structure, which is assembled into the retainer 10a. 
Meanwhile, the second connection mechanism portion 10d2 is formed integrally with a rear portion of the operation knob 12, which is assembled to the horizontal blade 11 to be slidable in the horizontal direction. The second connection mechanism portion 10d2 includes left and right outside connection arm portions 12a and 12b projecting rearward with a predetermined horizontal space formed therebetween, and a center connection arm portion 12c located between the connection arm portions 12a and 12b and dividing the space between the connection arm portions 12a and 12b into left and right engagement grooves 12a1 and 12b1. The center connection arm portion 12c is slightly shorter than the connection arm portions 12a and 12b, and its projection end portion is formed into a conical shape.
The first connection mechanism portion 10d1 is operationally connected to the second connection mechanism portion 10d2 in a state where the connection pillar portions 13c and 13d are inserted into the corresponding engagement grooves 12a1 and 12b1 of the second connection mechanism portion 10d2.
The connection mechanism 10d operates as follows. When the operation knob 12, assembled to the horizontal blade 11, is slid leftward or rightward, the operation knob 12 pushes the connection pillar portions 13c and 13d, inserted into the corresponding engagement grooves 12a1 and 12b1, leftward or rightward to thereby swing the vertical blade 13 leftward or rightward. During this operation, one of the connection pillar portions 13c and 13d, pushed by the center connection arm portion 12c, moves within the corresponding engagement groove toward the opening portion side. When the vertical blade 13 swings by a predetermined amount, one of the connection pillar portions 13c and 13d passes over the tip end of the center connection arm portion 12c and moves outside toward one of the connection arm portions 12a and 12b, while the other of the connection pillar portions 13c and 13d moves toward the base end portion of the corresponding engagement groove, and is pushed by the other of the outside connection arm portions 12a and 12b. 
Incidentally, although the above-described structure of the first connection mechanism portion 10d1 of the connection mechanism 10d enables the first connection mechanism portion 10d1 to be molded integrally with the vertical blade group 10c between the stationary die half 10e1 and the movable die half 10e2 of the molding die 10e, with mutually facing portions of the stationary die half 10e1 and the movable die half 10e2 have having complicated shapes as indicated by the parting line PL. In this structure, since a plurality of narrow projections are present, a problem associated with the die strength may arise. Therefore, there is a demand for a structure of the connection mechanism 10d which simplifies the shape of the parting line PL to thereby improve the strength of the molding die 10e. 
In the above-described connection mechanism 10d, while the blades of the vertical blade groups 10c are swung in an interlocked manner, one of the connection pillar portions 13c and 13d is pushed so that the first connection mechanism portion 10d1 is moved from the side of the center connection arm portion 12c, of the second connection mechanism portion 10d2, to one of the connection arm portions 12a and 12b. At that time, the load acting on the operation knob 12 changes suddenly. As a result, a person who operates the operation knob 12 feels a resistance during the operation, which impairs the operation feel. Therefore, the connection mechanism 10d is demanded to have a structure which can improve the operation feel of the operation knob 12.
Further, since the first connection mechanism portion 10d1 of the connection mechanism 10d has the above-described structure, a blade portion which functions as a vertical blade is not present between the upper and lower support plate portions 13a and 13b. Therefore, when the vertical blade group 10c is swung, a guide passage which causes air to flow straight is formed between the upper and lower support plate portions 13a and 13b, as indicated by alternate long and short dash lines in FIG. 8B. As a result, the connection mechanism 10d impairs the air-directing function of the register 10. Therefore, the connection mechanism 10d is demanded to have a structure which can improve the air-directing function.